Valle di Avigna
Very scenic but also very hard route, especially the challenging climb along the Avigna valley.
From the soccer field in Calva you go up along the bicycle path to Tubre. From here you take to the Avigna valley on a very steep road, then on a forest road. The valley is very beautiful and almost completely rideable to the top, minus the last 20 minutes to push up to the Crocetta pass.
From here an initially challenging trail leads into Switzerland. At the fork go up on forestry to the Costainas pass with nice views, then quick descent to the village of Lü. Here watch out for the fork and climb up on the left to avoid the valley floor asphalt and go for the nice finle path down to Müstair, with the beautiful monastery. Cross the border on the bike path and return to the start, not without taking one last nice trail through the forest.